Polyoxyethylene siloxane branch copolymers



United States Patent 0 3,518,288 POLYOXYETHYLENE SILUXANE BRANCHCOPOLYMERS Loren A. Haluska, Midland, Mich, assignor to Dow CorningCorporation, Midland, Mich, a corporation of Michigan No Drawing, FiledMay 2, 1966, Ser. No. 546,548 Int. Cl. Ctl'if 7/10 US. Cl. 260-4482 5Claims ABSTRACT OF THE DISCLOSURE New siloxane polyalkylene oxidecopolymers are disclosed which are useful in the preparation of rigidpolyurethane foams. These new copolymers make it possible toconsistently produce uniform fine-celled foams having a high percentageof closed cells under a wide variety of manufacturing conditions.

This invention relates to an improved method for making rigidpolyurethane foams and an additive therefor.

One of the fastest growing industries in recent decades has been the onedirected to products made from foamed materials. These foam productshave found many diverse uses such as in filters for cigarettes, filtersfor air conditioning systems, fuel filters, thermal and cryogenicinsulations, sound insulation, structural and dimensional supports,laminated structures, protective packaging for fragile items, candleholders, bases for table decorations (center pieces), christmas treeornaments and toys. The foamed products are generally identified asbeing either of the flexible or rigid type, and can be of any of thebasic chemical classes of foams well known in the art. Not only doeseach chemical class of foam have its own peculiar problem, but also eachtype of foam (flexible or rigid) within that class has its own problems.To further complicate the picture, the particular intended utility ofthe foam usually demands some special considerations too.

As was pointed out above, this invention is directed to polyurethanefoams of the rigid type. It is an object of this invention to provide animproved method for making rigid polyurethane foams. Another object isto provide an additive useful for making rigid polyurethane foams. Stillanother object of this invention to provide an additive and methodwhereby it is possible to consistently produce uniform, fine-celledrigid polyurethane foams having a high percentage of closed cells undera wide variety of manufacturing conditions. It is a further ob ject toprovide an additive and method for making rigid polyurethane foamsadaptable to a wide range of foaming conditions and foaming systems,including both one-shot and prepolymer systems. Yet another object is toprovide an additive and method for making rigid polyurethane foams whichare superior for foamed-in-place applications by virtue of excellentflowability. Other advantages of the additive and method of thisinvention include hydrolytic and chemical stability in storage ormixtures with most systems; improved compatibility with foam ingredientsincluding additives such as viscosity stabilizers and flame-retardants;improved miscibility through greater retention of fluorocarbon blowingagents in mixes; and handling ease including desirable low viscosityideal for production equipment. Other objects and advantages of thisinvention will be apparent from the following detailed description.

More specifically, this invention relates to an improvement in a methodof making a rigid polyurethane foam which includes mixing together apolymer selected from the group consisting of hydroxylated polyestersand hyice droxylated polyethers, an organic polyisocyanate, a catalystand a blowing agent, the improvement comprising incorporating therein acompound selected from the group consisting of siloxanes having theaverage structural formulae in which formulae A is a hydrocarbon radicalfree of aliphatic unsaturation and contains from 1 to 10 carbon atoms, Ais a radical of the structure wherein D is an alkylene radical, G is aradical selected from the group consisting of the ll ll OCR, OCOR and--OilNHR radicals wherein -R is as defined above, f has an average valuefrom 9 to 30, a has an average value from 0 to 1, b has an average valuefrom 6 to 192, c has an average value from O to 30, d has an averagevalue from 3 to 30, and e has an average value from 1 to 30, the ratioof the OSi(SH units to the OSi(CH )A and/or OSi(CH A units in thesiloxane being in the range of 2:1 to 6:1.

This invention further relates to an additive for making improved rigidpolyurethane foams which is a compound selected from the groupconsisting of siloxanes having the average structural formulae 3)33)2]b[ 3) ]d 3)3 in which formulae R is a hydrocarbon radical free ofaliphatic unsaturation and contains from 1 to 10 carbon atoms, A is aradical of the structure -D(OC H ),G

wherein D is an alkylene radical, G is a radical selected from the groupconsisting of the o o -oc in, 0 OR and radicals wherein R is as definedabove, 1 has an average value from 9 to 30, a has an average value from0 to l, b has an average value from 6 to 192, c has an average valuefrom 0 to 30, d has an average value from 3 to 30, and e has an averagevalue from 1 to 30, the ratio of the OSi(CH units to the OSi(CH )Aand/or OSi(CH A units in the siloxane being in the range of 2:1 to 6:1.

As is apparent from the above defined process, the hydroxylatedmaterials and polyisocyanates which are reacted to form the urethanepolymer, the catalyst for promoting the reaction, and the blowing agentfor foaming 0 g the mixture, are all well known to those skilled in theart. 3 Since these materials do not go to the essence of this Hinvention, and since detailed listings and descriptions of 5 them existnumerous places elsewhere, no further mention 0 will be made of themhere. g

The siloxanes used in the above process, which consti- OCeHs tute theadditives of this invention, are new compounds. 0 These siloxanes can bereadily prepared by well known OgNHC3H1 methods. For example, they canbe prepared by reacting 0 the appropriate ESlH containing siloxane withthe appro- H priate polyethylene glycol having a terminally unsaturated-0 CNHCgHn aliphatic group on one end and an appropriate capping I groupon the other end, the reaction being carried out in O g 010E thepresence of a platinum catalyst in a suitable solvent.

While this type of reaction is generally well known to those and skilledin the art, the preparation of the siloxanes of this 0 invention will beillustrated in more detail in the examples for the benefit of the tyros.

The values of the various subscripts a, b, c, d, e and f have been setforth above and define the limits of the differing portions of thecopolymers so that the advantages and objects of this invention can beachieved.

Now in order that those skilled in the art may better understand how thepresent invention can be practiced, carbon radical free of aliphaticunsaturation which conthe followmg f p 'l gwen by way of fllustratlonand tains from 1 to 10 carbon atoms. For example, R can be not by way ofhmltatlon' h b h an alkyl, cycloalkyl, aryl, alkaryl or an aralkylradical. Aulpar.ts angpercems referred 3, t By way of illustration R canbe a mfithyl ethyl propyl and :2 l viscoslties measured at 25 C. no essot erwlse isopropyl, butyl, tertiary butyl, amyl, hexyl, heptyl, octyl,Spec EXAMPLE 1 nonyl, decyl, cyclopentyl, cyclohexyl, phenyl, naphthyl,tolyl, xylyl, 1mesityl, t-butylphenyl, benzyl, Z-phenylethyl To a flaskwas added 77.1 g. of or a Z-pheny propyl radical.

The A radical in the above formulae must have the(CH3)3S1[(CI-m2]7[OSI(CH3)H]3OS1(CH3)3 structure D(OC H );G. In thisstructure D is any alkyl- 175 of ene raldical. Igor example, It), can bea methylene, ethylene, E) propy ene, uty ene, iso utylene, hexylene, octlene, h dodecylene, octadecylene or a triacontylene ra c lical.CHPCHOHAOCZHWO (JJNHCZH Preferably, D contains from 3 to 18 carbonatoms. 2 fi h g? F' a In the Structur f h 0 p mum as c oropai c aci soulOIl 1n is pro- 6 o A t e G radical can be an acyloxy panol. Theforegoing mixture was heated at 78 to 95 C. for about 30 minutes,filtered, and then stripped to 149 -oc C. at 4 mm'. of mercury pressure.The product,

The siloxanes that will achieve the objects of this invention arerelatively few as should be apparent from the formulae supra. Thus, withthe exceptions of the R and A groups, essentially all substitutents onthe silicon atoms must be methyl radicals. 25

The R group in Formulae 1 and- 2 can be any hydrocarbonate ester had aviscosity of 279 cs., a refractive index of 1.4499 and O a specificgravity of 1.079. (-oilom EXAMPLE 2 or an isocyanate The procedure ofExample 1 was repeated except that 83.4 g. of the siloxane 3)a l a)2]9[3) ]a 3)3 was used and the reaction was carried out at -85 to radical.Of these, the acyloxy and isocyanate radicals are 110 C.

(CHs)aSi[O Si(CH:)2]vlO Si(CH:) CHzCHzCHKO 02110120 JNHCzHslaOSKCHDpreferred with the latter being the most preferred. Specific had aviscosity of 322 cs., a refractive index of 1.4487

illustrative example of the G group are and a specific gravity of 1.067.

0 EXAMPLE 3 g The procedure of Example 1 was repeated except that 0 73.7g. of the siloxane g (CH Si[OSi(CH [OSi(CH )H] OSi(CH 3 was used, 41.4g. of the n-propanol and toluene was used,

H the reaction was carried out at to 99 C. and the cc,H,, mixturestripped to 151 C. at 5 mm. of pressure. The

product,

had a viscosity of 545 cs., a refractive index of 1.4510 and a specificgravity of 1.074.

EXAMPLE 4 To a flask there was added 84.2 g. of

(CH Si[OSi(CH [OSi(CH )H] OSi(CH 188.7 g. of

O CH2=CHCHz(OC2Hi)14O (LCHa 45.4 g. of n-propanol, 45.4 g. of tolueneand 0.6 cc. of a 2% platinum .(as chloroplatinic acid) solution inisopropanol. The foregoing mixture was heated at 80 to 95 C. for about30 minutes, filtered. and then stripped to 160 C. at 6 mm. of mercurypressure. The product,

had a viscosity of 216 cs., a refractive index of 1.4480 and a specificgravity of 1.073.

EXAMPLE 5 When the siloxanes and unsaturated compounds specisiloxaneadditive of this invention followed by the addition of crude toluenediisocyanate in an amount equivalent to 105% of the hydroxyl groups inthe polyether (Le, a 5% excess of isocyanate was added). The aboveingredients were hand-mixed on a Hamilton Beach malttype mixer mountedon a drill press stand. Mixing time was five seconds at 2200 r.p.m.

In order to evaluate the characteristics of the rigid urethane foamsprepared in accordance with this invention, immediately afterpreparation (supra) they were poured into an L-shaped mold having a 10/2 inch by inch base and a 10 /2 inch by 24 inch vertical leg, both baseand leg being 1 inch deep. The mold was lined with apolytetrafiuoroethylene coated fabric sheet and coated with a thin layerof paste wax for release. At the forward part of the mold is a threeinch hinged flap where the foam ingredients were poured. The ingredientswere poured into the mold for a period of five seconds, the flapimmediately closed and clamped, and the foams allowed to rise and curefor about ten minutes before releasing. The quart cups containing theexcess foam were weighed after pouring to fied below are reactedfollowing the procedure of the 25 insure that all panels were of equalcharge or quantity.

preceding examples, the indicated product is obtained.

In the L-shaped mold, the foam must travel horizontally II (0 CgHQwOCNHCtHD EXAMPLE 6 A mixture of 1933 parts of a sucrose polyether, 76.3parts of monofiuorotrichloromethane, 3.1 parts of a 33% solution oftriethylenediamine in dipropylene glycol and 2.1 parts ofdimethylaminoethanol was placed in a one 7 along the base of the mold,round a 90 corner, and then travel vertically. The narrowness of themold and the cornering place shearing effects on the rising foam masswhich simulate cast-in-place use conditions. After the foam had cured,it was removed from the mold and cut in half quart Dixie cup. There wasthen added 2.0 parts of the vertically. First the height to which thefoam rose was measured. One-half was then cut horizontally 3 /2 inchesabove the base. At this point maximum flow lines (striations) areobserved and are rated. The size of the cells in the foam was alsorated. The following scale was used in the evaluations.

(A) The siloxane of Example 2 (B) The siloxane of Example 3 (C) Thesiloxane of Example 4 In the table below the evaluations of the siloxaneadditives above is set forth.

Height (inches) Cells Additive q oowzaeaomom Flow lines EXAMPLE 7 Whenthe compounds of Example 5 are substituted for those of Example 6,similar results are obtained.

That which is claimed is:

1. A compound selected from the group consisting of siloxanes having theaverage structural formulae R is a hydrocarbon radical free of aliphaticunsaturation and contains from 1 to 10 carbon atoms, A is a radical ofthe structure 0 D(OC2H4)IO iiNHR wherein D is an alkylene radical, R isas defined above, fhas an average value from 9-3 0, a has an averagevalue from 0 to 1, b has an average value from 6 to 192, c has anaverage value from 0 to 30, d has an average value from 3 to 30, and ehas an average value from 1 to 30, the ratio of the OSi(CH units to theOSi(CH )A and/ or OSi(CH A units in the siloxane being in the range of2:1 to 6:1.

2. A compound as defined in claim 1 which has Formula 3.

3. A compound as defined in claim 2 wherein D is a propylene radical, fis about 12 and R is C H 4. A compound as defined in claim 1 which hasFormula 4.

5. A compound as defined in claim 4 wherein D is a propylene radical, fis about 12 and R is C H References Cited UNITED STATES PATENTS2,834,748 5/1958 Bailey et al 260448.2 X 2,839,558 6/1958 Kirkpatrick eta1. 260448.2 X 2,846,458 8/ 1958 Haluska. 3,168,543 2/1965 Black et a1260-4482 3,298,919 l/1967 Bishop et al 26046.5 3,402,192 9/ 1968Haluska.

TOBIAS E. LEVOW, Primary Examiner P. F. SHAVER, Assistant Examiner US.Cl. X.R. 2602.5

